Antenna for chip card production

ABSTRACT

The present invention relates to an antenna arrangement ( 10 ) for the production of chip cards, in particular chip cards used in the UHF frequency range, having a substrate and a plurality of antenna conductor structures ( 11 ) formed on the substrate using a coating method, the antenna conductor structures having a terminal arrangement ( 24 ) for connecting the antenna conductor structures to a chip, wherein the substrate is formed as a substrate sheet ( 12 ), and the antenna conductor structures are disposed on the substrate sheet in a matrix arrangement ( 13 ) having a plurality of columns and rows.

The present invention relates to an antenna arrangement for theproduction of chip cards, in particular chip cards used in the UHFfrequency range, having a substrate and a plurality of antenna conductorstructures formed on the substrate using a coating method, the antennaconductor structures having a terminal arrangement for connecting theantenna conductor structures to a chip.

Antenna arrangements of the above-cited type are utilized in particularin the implementation of the antenna conductor structure in the form ofa dipole arrangement in transponders which are operated in the UHFfrequency range. Due to the formation of the antenna conductorstructures using a coating method, and provided that the antennasubstrate, which may for instance also be formed by a foil, is designedwith an adequate degree of flexibility, the antenna arrangements of theabove-cited type also feature a special suitability for the productionof so-called tags, which are frequently employed for product labelingand which are planarly applied to the surface of the product to belabeled. Irrespective of the embodiment of the transponder, in which theantenna conductor structure produced using a coating method is used, inthe production of the transponders, i.e. for instance of the chip cardsor tags, it has hitherto been common practice for producing a pluralityof transponders to dispose the antenna conductor structures in a rowarrangement on a carrier strip designed in the form of an infinitesubstrate. In the production of the transponders, the carrier stripbeing rolled up to form a supply roll is continuously unwound and theantenna conductor structures are separated from the supply roll bycutting off substrate segments.

Subsequently, contacting of the antenna conductor structures disposed onthe separated antenna substrates with a chip module is performed andcover layers covering the antenna substrate on both sides are appliedfor producing the chip card or the tag.

The known method thus necessitates the handling of the antennasubstrates separated from the supply roll for producing the transponder,i.e. for instance the chip card or the tag. This handling of theseparated antenna substrates is a laborious procedure in particular ifsubsequent to the separation, for preparing a lamination process, theseparated antenna substrates are applied to cover layers which arecoherently formed in a panel structure, since for each cover layer inthe panel structure, the assigned antenna substrate needs to bepositioned differently.

Thus, it is an object of the present invention to suggest an antennaarrangement which enables a simplified production of transponders usinga lamination method.

To achieve this object, the inventive antenna arrangement encompassesthe features of claim 1.

In the inventive arrangement, the substrate is formed as a substratesheet and the antenna conductor structures are disposed in a matrixarrangement having a plurality of columns and rows on the substratesheet, so that simultaneous positioning of a plurality of antennaconductor structures disposed in a matrix arrangement can be performedon a cover layer substrate having cover layers disposed in a matrixstructure.

Due to the antenna arrangement designed according to the invention, itis hence possible to dispense with the need for positioning eachseparated antenna substrate individually for the purpose of a congruentarrangement with an assigned cover layer. Instead, it is sufficient toproduce a congruent arrangement of the antenna conductor structuresdisposed in a matrix arrangement with the cover layers disposed in acorresponding matrix arrangement in a single positioning step. If thecover layers, which serve the purpose of covering the antenna conductorstructure on the antenna substrate in an insulating manner, are equippedwith a chip or are for instance entirely formed as a chip module inwhich the cover layer serves as a carrier substrate for the chip, it ispossible to carry out a positioning alignment of the terminalarrangement of the antenna conductor structure with the terminal facesof the chip simultaneously with the arrangement of the plurality ofantenna conductor structures on the cover layer structure for subsequentcontacting of the chip with the antenna conductor structure.

The antenna arrangement proves to be particularly advantageous if theantenna conductor structure features at least one dipole arrangement,since thus the production of UHF transponders is possible in alamination process, without the need for handling the separated antennasubstrates. In particular if the dipole arrangement is designed in anasymmetric fashion, a handling of the antenna conductor structures,which are disposed on the antenna substrate in a coherently formedstructure, proves to be easier compared to the handling of separatedantenna conductor structures due to the unfavorable center-of-gravitydistribution resulting from the asymmetry.

If the dipole arrangement is formed of a wire conductor, the productionof the dipole arrangement is rendered possible by laying the wireconductor on the surface of the substrate sheet.

In a preferred embodiment, the antenna arrangement comprises theformation of a dipole arrangement, which features a first antenna strandand a second antenna strand, which each extend longitudinally along acolumn separation line and a row separation line for separating theantenna conductor structures, and which are connected to one another inan intersection zone of the separation lines via a coupling conductorsection. Antenna conductor structures designed in this manner enable anoptimized arrangement in an edge region of the antenna substrate, whichsignificantly minimizes the risk that parts of the dipole arrangement ofthe antenna conductor structure are covered due to the grasping hand incase of manually grasping a transponder which is designed as a chipcard.

By means of the aspect that the antenna conductor structure is disposedremote from a “grasping zone” in a lateral edge region of the substrate,it is possible to grasp the card from at least one lateral edge of thechip card in a normal manner, i.e. by placing the thumb or at least onefinger in the central region of the card, without giving rise to theinevitable consequence that the antenna is detuned. In the preferredembodiment, by means of the arrangement of the extremely asymmetricaland eccentric antenna conductor structures in a common matrixarrangement, the antenna arrangement enables the effortless handling ofthe antenna conductor structures in the production of the chip cards ina lamination process.

If, according to a particularly preferred embodiment of the antennaarrangement, the terminal arrangements for connecting the antennaconductor structures to the chip are designed in the from of a loopdipole having a coupling conductor section which is disposed in parallelto the coupling conductor section of the assigned antenna conductorstructure, it is possible to dispose the terminal arrangements,respectively the chip contacted with the terminal arrangement, laterallyto the antenna strands of the antenna conductor structure, so that withthe aid of the antenna arrangement chip cards can be produced which havean antenna conductor structure, the antenna strands of which can be laidso as to substantially reach the lateral edge of the antenna substrate,in order to realize chip cards having an extremely large grasping zone.

If the terminal arrangements in the antenna arrangement feature at leasttwo planarly formed terminal contacts, which extend via a substraterecess being open towards a substrate rear side, direct contacting ofthe antenna conductor structure with a component, for instance a chip,which is disposed on the rear side of the antenna substrate, i.e. on theside opposite to the antenna conductor structure, can be carried outwithout any further recontacting or rewiring. The terminal arrangementapplied to the frontal side of the antenna substrate using a coatingmethod essentially straddles the substrate recesses, which are freelyaccessible from the rear side of the antenna substrate, so that directcontacting of the terminal contact rear sides can be performed.

This arrangement, which straddles the substrate recesses, for instancecan be produced by the aspect that prior to the application of theantenna conductor structure, respectively the terminal arrangement onthe antenna substrate, recesses realized in the antenna substrate aretemporarily filled with the antenna material during the coating of theantenna substrate.

If the terminal contacts are applied on the card substrate integrallywith the coupling conductor section of the terminal arrangement as amaterial coating using a coating method, in spite of the arrangement ofthe terminal contacts straddling the substrate recesses, a sufficientlyhigh degree of mechanical stability is attained.

In general, it proves to be advantageous if the antenna conductorstructure and the terminal arrangement formed therein are formed of acongruent material coating, since thus the entire antenna conductorstructure can be produced in a single coating step.

If the terminal arrangement is formed of aluminum or an alloy containingaluminum, in particular in the instance where the chip provided for thecontacting with the terminal arrangement equally features terminalcontacts of aluminum or of an alloy containing aluminum, a directcontacting of the chip terminal faces with the terminal contacts of theterminal arrangement can be carried out using an ultrasonic weldingmethod.

If the terminal arrangement is formed of copper or an alloy containingcopper, a contacting with a chip by means of a commonly used thermalbonding method is practicable.

It proves to be particularly advantageous if the antenna arrangement isconfigured as a laminate structure having two substrate sheets whicheach feature the terminal arrangements, respectively the dipolearrangements. Thus, variability of the local assignment of the terminalarrangements and the dipole arrangements in the plane of the substratesheets is realizable, which permits the setting of the distance betweenthe terminal arrangements and the dipole arrangements for the purpose offrequency tuning of the antenna conductor structures.

By the same token, it is possible to modify the local assignment of thedipole arrangement to adjacent laminate layers in the laminate structureof a chip card, in order to lay the dipole arrangements in selectedregions of the chip card, in order to dispose the dipole arrangementremote from a “grasping zone” for instance in order to prevent detuningof the dipole arrangement.

Hereinafter, a preferred embodiment of the antenna arrangement will bedescribed in more detail with reference to the drawings.

In the drawings:

FIG. 1 shows an antenna arrangement having a plurality of antennaconductor structures which are disposed in a matrix arrangement on asubstrate sheet;

FIG. 2 shows an antenna substrate which has been separated from thesubstrate sheet;

FIG. 3 shows a cross-sectional view of a chip card produced on the basisof the antenna substrate illustrated in FIG. 2 according to intersectionlines III-III in FIG. 2;

FIG. 4 shows another chip card in a view according to FIG. 3;

FIG. 5 shows an antenna substrate during the coating with a metalliccoating applied to the substrate for the formation of the antennaconductor structure;

FIG. 6 shows a schematical view of a method for producing chip cards onthe basis of an antenna arrangement formed on a substrate sheet.

FIG. 1 shows an antenna arrangement 10 having a plurality of antennaconductor structures 11, which are disposed on a substrate sheet 12 in amatrix arrangement 13. The matrix arrangement 13 in the present casecomprises six rows 14 and three columns 15. The 6×3 matrix arrangement13 illustrated in FIG. 1 encompasses a total of eighteen antennaconductor structures 11, which are each arranged on an antenna substrate16 in such a manner that the antenna substrates 16 in their entiretyform the substrate sheet 12. The dimensions of the antenna substrates 16are defined by column separation lines 17 and row separation lines 18,which form predetermined separation lines for a subsequent separation ofthe antenna substrates 16 from the structure formed by the substratesheet 12.

The material used for the substrate sheet 12 as well as for the furthermentioned cover layers or chip carriers may for instance be PVC, PETG orelse also a polycarbonate.

The individual antenna conductor structures 11 each feature a dipolearrangement 23, having an antenna strand 19 which extends longitudinallyalong a column separation line 17 and a second antenna strand 20 whichextends longitudinally along a row separation line 18. The antennastrands 19, 20 are connected to one another via a coupling conductorsection 21 which extends in sections essentially in parallel to thecolumn separation line 17, respectively the row separation line 18, andwhich extends adjacent to an intersection zone 22 which is formed by thecolumn separation line 17 and the row separation line 18. Adjacent tothe coupling section 21 of the dipole arrangement 23, the terminalarrangement 24 is disposed, which in the present case is designed as aloop dipole and has planarly formed terminal contacts 25, 26.

As can be seen from the illustration of an antenna substrate 16separated from the substrate sheet 12 in FIG. 2, the antenna strands 19,20 at their free ends each feature open conductor loops, respectivelyconductor frames, which in the case at hand, are formed with differentsizes and thus enable different frequency tuning of the dipolearrangement 23 which is respectively assigned to the antenna strands 19,20.

The antenna substrate 16 illustrated in FIG. 2 features a substratesurface 29 which is divided into a grasping zone 30 and a transponderzone 31. Here, the grasping zone 30 refers to the region where at leastpartial covering of the antenna surface 29 can be performed by the thumbor the finger when a card user grasps the antenna substrate 16,respectively the chip card formed on the basis of the antenna substrate,without the consequence of a covering of the dipole arrangement 23,respectively the antenna conductor structure 11, which are accommodatedin the transponder zone 31.

In the antenna substrate 16 illustrated in FIG. 2, the transponder zone31 is formed substantially with an L-shape and accommodates the antennaconductor structure 11. Due to the L-shaped design of the transponderzone 31, the antenna conductor structure 11, respectively the dipolearrangement, merely extends directly adjacent to the lateral edges 32,33 of the antenna substrate 16 in such a manner that a large degree ofvariability is enabled in the access to the antenna substrate 16,respectively the chip card formed therefrom, without giving rise to acovering of parts of the dipole arrangement 23 by the thumb or fingersof the grasping hand.

As is also apparent from the illustration according to FIG. 2, in theantenna substrate 16 substrate recesses 34, 35 and 36 are each formedbeneath the terminal contacts 25 and 26 as well as between the terminalcontacts 25, 26. As is shown in FIG. 3, the substrate recesses 34, 35serve for direct contacting with terminal conductors 38, 39 of a chipcarrier 40 when a chip card 37 is formed on the basis of the antennasubstrate 16. In this context, the terminal conductors 38, 39, in thecase at hand, are contacted, with the aid of raised contacts formed onthe terminal conductors 38, 39, with a contact rear side 42 of theterminal contacts 25, 26 in a direct manner, i.e. on a straight contactaxis 43 without axial displacement as would be the case in the event ofrewiring.

As is also apparent from FIG. 3, the substrate recess 36 formed betweenthe terminal contacts 25, 26 in the antenna substrate 16 serves thepurpose of accommodating a chip 44 which is contacted with the terminalconductors 38, 39 via its chip contacts 45, 46.

In the chip card 37 illustrated in FIG. 3, a chip module 47 is providedfor contacting between the antenna substrate 16, respectively theterminal arrangement 24, of the antenna conductor structure 11 formed onthe antenna substrate 16, in such a manner that the chip 44 in thesubstrate recess 36 is accommodated between a rear side 48 of a firstcover layer 49 applied to the antenna conductor structure 11 and thechip carrier 40. The chip carrier 40 as such is accommodated between arear side 50 of the antenna substrate 16 and a second cover layer 51applied to the rear side 50.

FIG. 4 shows a chip card 52 which differs from the chip card 37illustrated in FIG. 3 in that, here, a chip module 61 is used, which hasa chip carrier 53 that features dimensions being in conformity with theantenna substrate 16 and thus simultaneously forms a cover layer.

FIG. 5 shows an antenna substrate 16 directly after the realization of acoating of the antenna substrate 16 with a metallic conductor material54 for the formation of the antenna conductor structure 11, respectivelythe terminal arrangement 24. Already prior the realization of thecoating, in the antenna substrate 16 the substrate recesses 34, 35 and36 are provided, wherein at least the substrate recesses 34, 35, whichserve for the subsequent contacting with the chip 44, are filled duringthe coating process, in order to prevent the conductor material 54 frompenetrating into the substrate recesses 34, 35. This can be performed bythe aspect that, during coating, the antenna substrate 16 is disposed ona substrate carrier 55 which is provided with projections 56, 57 whichengage into the substrate recess 34, 35 in a positive fitting manner.The projections 55, 56 at least on their coating surface are providedwith an anti-adhesion coating, so that upon removal of the substratecarrier 55 from the antenna substrate 16, the arrangement of theterminal contacts 25, 26 illustrated in FIG. 5, which straddles thesubstrate recesses 34, 35, is preserved.

FIG. 6 is supposed to once again highlight the sequence of theindividual method steps, which are necessary for instance for theproduction of the chip card 52 illustrated in FIG. 4.

Firstly, an arrangement of a substrate sheet 12 having a plurality ofantenna conductor structures 11 disposed in a matrix arrangement 13 on achip module sheet 59 is performed, which features a plurality of chipmodules 61 disposed in a structure and which corresponds to the numberof antenna conductor structures 11. The terminal conductors 38, 39 ofthe individual chip modules 61 are here arranged in such a manner thatthe raised contacts 41 disposed thereon are positioned so as to overlapthe terminal contacts 25, 26 of the antenna conductor structures 16 insuch a manner that upon arrangement of the substrate sheet 12 on thechip module sheet 59, the raised contacts 41 engage into the substraterecesses 34, 35. Subsequently, for instance by means of subjecting theterminal contacts 25, 26 to ultrasound from their upper side, a weldingof the terminal contacts 25, 26 with the raised contacts 41 of theterminal conductors 38, 39 can be performed. Subsequently, a cover layersheet 60 can be applied to the substrate sheet 12 from above, in orderto complete the laminate structure for the production of a number ofchip cards which corresponds to the matrix arrangement.

For separating the individual chip cards 52 from the thus produced chipcard structure, a separating and cutting process is subsequentlyperformed along the row separation lines 18 and the column separationlines 17 of the substrate sheet 12.

1. An antenna arrangement for the production of chip cards, inparticular chip cards used in the UHF frequency range, said arrangementcomprising: a substrate; and a plurality of antenna conductor structuresformed on the substrate, the antenna conductor structures having aterminal arrangement for connecting the antenna conductor structures toa chip (44), wherein the substrate is formed as a substrate sheet, andthe antenna conductor structures are disposed on the substrate sheet ina matrix arrangement having a plurality of columns and rows.
 2. Theantenna arrangement according to claim 1, in which the antenna conductorstructures feature at least one dipole arrangement.
 3. The antennaarrangement according to claim 2, in which the dipole arrangement isformed of at least one wire conductor.
 4. The antenna arrangementaccording to claim 2, in which the dipole arrangement features a firstantenna strand and a second antenna strand, which each extendlongitudinally along a column separation line and a row separation linefor separating the antenna conductor structures, and which are connectedwith one another in an intersection zone of the separation lines via acoupling conductor section.
 5. The antenna arrangement according toclaim 4, in which the terminal arrangements for connecting the antennaconductor structures to the chip are formed as a loop dipole having acoupling conductor section which is disposed in parallel to the couplingconductor section of the assigned antenna conductor structure.
 6. Theantenna arrangement according to claim 1, in which the terminalarrangements feature at least two planarly designed terminal contacts,which extend over substrate recesses being open towards a substrate rearside.
 7. The antenna arrangement according to claim 6, in which theterminal contacts are applied to the antenna substrate in the form of amaterial coating using a coating method and are formed integrally withthe coupling conductor sections of the terminal arrangements.
 8. Theantenna arrangement according to claim 7, in which the antenna conductorstructures and the terminal arrangements are formed of a congruentmaterial coating.
 9. The antenna arrangement according to claim 1, inwhich the terminal arrangements are formed of aluminum or of an alloycontaining aluminum.
 10. The antenna arrangement according to claim 1,in which the terminal arrangements are formed of copper or of an alloycontaining copper.
 11. A laminate structure for the production of chipcards, comprising an antenna arrangement according to claim 2, in whichthe terminal arrangements and the dipole arrangements of the antennaconductor structures are formed on separate substrate sheets which areplanarly connected to one another for the production of the antennaconductor structures.